Nouvelle transmission 6 vit pour GM: DSG ?

[STONE_COLD]

Je suis pas expert en mécanique mais quelqu'un pourrait dire si c'est comparable à la boîte DSG de VW.


MILFORD, Mich. – General Motors new Hydra-Matic 6T70 six-speed automatic transmission, an advanced transmission with clutch-to-clutch shift operation for front- and all-wheel drive vehicles, will debut in the all-new 2007 Saturn Aura midsize sedan. Co-developed with Ford Motor Co., the new six-speed joins the already announced Hydra-Matic six-speed rear-wheel drive family of automatics and Allison 1000 six-speed automatic as part of GM’s mission to produce 3 million six-speed automatics annually by 2010.

“The 6T70 offers the best of both worlds – the excitement of a performance transmission and the economy expected of an overdrive,” said Robert Vargo, assistant chief engineer, new front-wheel drive transmissions. “The joint development effort allowed both companies to maximize time and engineering talent to answer a common need for a fuel-efficient transmission that meets the performance needs of high-output, transverse-mount powertrains.”

[Alain36]

Chez Ford, ça va remplacer les actuelles transmissions de la Five-Hundred et Freestyle, entre autres. Non, ce n'est pas une DSG.

[Stan Marsh]

Rien de mieux que le brevet du concept "clutch-to-clutch shift operation"

http://www.freepatentsonline.com/4796490.html

A clutch-to-clutch power-on downshift in a motor vehicle automatic transmission is initiated by reducing the torque capacity of the off-going clutch, permitting the transmission input speed to increase toward its post shift value. When the slippage across the off-going clutch exceeds a reference, the reduction of its torque capacity is suspended, permitting continued increase of the transmission input speed. When the slippage across the on-coming clutch falls below a reference value, the on-coming and off-going clutches are concurrently applied and released to complete the shift. The transmission input speed substantially achieves its post shift value at the time of such apply and release, resulting in reduced shift-related output torque disturbance.

À ce que je vois, c'est une transmission automatique "amélioré" (moins de perte de puissance lors des passage de vitesse). Dommage pour ceux qui rêvait d'une DSG américaine... La Corvette 2006 va avoir aussi ce type de technologie.

En passant, notez que GM a déposé son brevet à la fin des années 80... Une autre example que le domaine automobile est lent à bouger...